Fig. 7.

miR-1; miR-9a double mutants display ventral midline defects. Wild-type (left) and miR-1; miR-9a double-mutant (right) embryos of increasing age (A-E) were hybridized with rho probes. Yellow arrowheads in B indicate dorsal expression of rho. In the nc 14 embryo (A), rho expression is detected in two ventrolateral stripes, which come together during ventral furrow formation in stage 8-10 embryos (B-D), forming the ventral midline. rho is expressed in tracheal pits (tp, black arrows) after stage 11 (E). miR-1; miR-9a double-mutant embryos are defective in synchronized ventral midline closure, as anterior and posterior gaps are visible (B, red arrows). Ectopic rho expression is observed along the midline (C, pink arrowheads).